Effects of stimulation by three-dimensional natural images on prefrontal cortex and autonomic nerve activity: a comparison with stimulation using two-dimensional images

Empirical evidence suggests that three-dimensional (3D) images of nature promote physiological relaxation in humans by providing more realistic effects compared with two-dimensional (2D) images. However, no studies have evaluated the physiological relaxation effects of nature-derived 3D images on prefrontal cortex and autonomic nerve activity. The present study aimed to clarify the physiological relaxation effects of visual stimulation by 3D flower images on prefrontal cortex and autonomic nerve activity. Nineteen male university students (22.2 ± 0.6 years) were presented with 3D and 2D images of the water lily for 90 s. Prefrontal cortex activity was measured using near-infrared spectroscopy, while autonomic nerve activity was measured using heart rate variability (HRV). Psychological effects were determined using a modified semantic differential method (SD). Compared with visual stimulation by 2D images, that by 3D images resulted in a significant decrease in oxyhemoglobin concentration in the right prefrontal cortex, lower sympathetic activity as calculated by the ratio of the low-frequency to high-frequency HRV component, and a significantly greater realistic feeling as evidenced by higher SD ratings. In conclusion, visual stimulation by realistic 3D floral images promotes physiological relaxation more effectively than the corresponding 2D image.     

Synaptic plasticity in hippocampal CA1 neurons of mice lacking type 1 inositol-1,4,5-trisphosphate receptors

In hippocampal CA1 neurons of wild-type mice, delivery of a standard tetanus (100 pulses at 100 Hz) or a train of low-frequency stimuli (LFS; 1000 pulses at 1 Hz) to a naive input pathway induces, respectively, long-term potentiation (LTP) or long-term depression (LTD) of responses, and delivery of LFS 60 min after tetanus results in reversal of LTP (depotentiation, DP), while LFS applied 60 min before tetanus suppresses LTP induction (LTP suppression). To evaluate the role of the type 1 inositol-1,4,5-trisphosphate receptor (IP3R1) in hippocampal synaptic plasticity, we studied LTP, LTD, DP, and LTP suppression of the field excitatory postsynaptic potentials (EPSPs) in the CA1 neurons of mice lacking the IP3R1. No differences were seen between mutant and wild-type mice in terms of the mean magnitude of the LTP or LTD induced by a standard tetanus or LFS. However, the mean magnitude of the LTP induced by a short tetanus (10 pulses at 100 Hz) was significantly greater in mutant mice than in wild-type mice. In addition, DP or LTP suppression was attenuated in the mutant mice, the mean magnitude of the responses after delivery of LFS or tetanus being significantly greater than in wild-type mice. These results suggest that, in hippocampal CA1 neurons, the IP3R1 is involved in LTP, DP, and LTP suppression but is not essential for LTD. The facilitation of LTP induction and attenuation of DP and LTP suppression seen in mice lacking the IP3R1 indicates that this receptor plays an important role in blocking synaptic potentiation in hippocampal CA1 neurons.     

Unequal but not separate: Emergence of rich–poor cooperation in resource exchange

Addressing inequality is a critical challenge for society as a whole and requires sustained efforts to promote fairness and opportunity for all. Filling in the resource gap across social classes is essential in reducing inequality. Previous studies have revealed that ingroup favouritism hinders the rich from cooperating with the poor and expands the wealth gap. Nevertheless, how to find ways of narrowing the gap between the rich and the poor remains an open question. Inducing rich–poor cooperation could be effective in eliciting resource flow across classes. In this study, two experiments using a modified Prisoner's Dilemma game were conducted in Japan (N = 213) and China (N = 150) to examine whether highlighting partners' cooperativeness under permeable group boundaries induces rich–poor cooperation. All participants were allocated to the rich group and participated in the game with programmed rich- or poor-group partner bots, whose cooperation rates were manipulated. Despite the initial resource disparities between participants and the partner bots, participants were more likely to select and cooperate with cooperative poor-group partners than with non-cooperative rich-group partners. Generalized trust played an important role in the enhancement of rich–poor cooperation. The findings shed light on the possibility of reducing inequality and promoting social mobility in society.     

Assessing the influence of schematic drawings of body parts on tactile discrimination performance using the crossmodal congruency task

Seeing one's own body (either directly or indirectly) can influence visuotactile crossmodal interactions. Recently, it has been shown that even viewing a simple line drawing of a hand can also modulate such crossmodal interactions, as if the picture of the hand somehow corresponds to (or primes) the participants' own hand. Alternatively, however, it could be argued that the modulatory effects of viewing the picture of a hand on visuotactile interactions might simply be attributed to cognitive processes such as the semantic referral to the relevant body part or to the orientation cues provided by the hand picture instead. In the present study, we evaluated these various different interpretations of the hand picture effect. Participants made speeded discrimination responses to the location of brief vibrotactile targets presented to either the tip or base of their forefinger, while trying to ignore simultaneously-presented visual distractors presented to either side of central fixation. We compared the modulatory effect of the picture of a hand with that seen when the visual distractors were presented next to words describing the tip and base of the forefinger (Experiment 1), or were superimposed over arrows which provided another kind of directional cue (Experiment 2). Tactile discrimination performance was modulated in the hand picture condition, but not in the word or arrow conditions. These results therefore suggest that visuotactile interactions are specifically modulated by the image of the hand rather than by cognitive cues such as simply semantic referral to the relevant body sites and/or any visual orientation cues provided by the picture of a hand.     

Fragility of Happiness Beliefs Across 15 National Groups

The belief that happiness is fragile—that it is fleeting and may easily turn into less favourable states—is common across individuals and cultures. However, not much is known about this belief domain and its structure and correlates. In the present study, we use multigroup confirmatory factor analysis and multilevel modelling to investigate the measurement invariance, cross-level isomorphism, predictive validity, and nomological network of the fragility of happiness scale across 15 nations. The results show that this scale has good statistical properties at both individual and cultural levels, and is associated with relevant psycho-social concepts in expected directions. The importance of the results, limitations, and potential directions for future research are discussed.     

Processes of Social Influence on Sampling Behavior: The Effect of Other's Positive Attitude and Receiver's Prior Experience

Studies about attitude formation have pointed out the importance of sampling behavior. When thinking about actual social interaction scenes, it may be better to consider them as attitude-updating processes between those who have already formed attitudes based on some experience. Sixty-five participants took part in the experiment, in which the other's positive attitude and the participant's own prior experience were manipulated. After participants had been presented five types of puzzles (experience: direct vs. indirect), which had been made to improve analytic ability, their attitudes towards the puzzles were measured (“pre attitude”). They were shown the other's positive attitude (inconsistent vs. consistent), and they were given 10 min of free time before “testing on their analytic ability.” The amount of time spent on each puzzle was recorded to index sampling behavior and the attitudes towards the puzzles were measured after the free time (“post attitude”). The results of analyses showed that the other's positive attitude increased sampling behavior when the participant's attitude was positive (first-ranked) and negative (fifth-ranked), and that prior experience and sampling contributed to attitude change for the first-ranked puzzle. Those who had had direct experience and those who had spent more time sampling this puzzle tended to maintain their previous positive attitude. The potential boundary conditions of social influence on sampling behavior are discussed.     

Territorial Conflicts and Japanese Attitudes Towards East Asian Countries: Natural Experiments with Foreigners' Landings on Disputed Islands

Japan disputes the sovereignty of two islands: Senkaku/Diaoyu with China and Takeshima/Dokdo with South Korea. These disputes have triggered political performances. In August 2012, Chinese activists landed on Senkaku/Diaoyu, and South Korean politicians landed on Takeshima/Dokdo. The group threat theory suggests that these events constitute threats to Japanese citizens, which lead to negative attitudes towards these countries. The theory also expects personal variations in the reactions to the threats, and the empirical findings of the theory predict an improvement in the worsened attitudes immediately after the event. Drawing on a Japanese social survey that was conducted every month for the two years during which these landing events occurred, I tested the effect of the events on Japanese attitudes towards China and South Korea in a natural experimental framework. The results show that the events negatively impacted Japanese attitudes towards both countries. However, contrary to the expectations of the group threat theory, individual variations (i.e., socioeconomic status, media exposure, and political orientation) in the responses to the events are not supported. Additionally, the attitudes do not return to preevent levels for one year. The contradictions between previous studies and this study potentially originate from the importance of the territories.     

“Paying it forward” via satisfying a basic human need: The need for relatedness satisfaction mediates gratitude and prosocial behavior

People who receive kindness tend to feel gratitude and act in a prosocial manner toward third persons (i.e., “paying it forward”). Combining the separate evidence that (a) gratitude leads to the formation of strong psychological bonds from a beneficiary to a benefactor and that (b) people become more prosocial toward strangers when the need for relatedness (NFR) is satisfied, two online experiments were conducted to examine if NFR satisfaction mediates the association between gratitude and prosocial behavior toward third persons. After evoking gratitude by recalling past experiences (Study 1) or writing a letter to someone (Study 2), participants were asked to make a donation from their remuneration for the experiment to a charity organization. As predicted, emotional manipulation promoted donation via feelings of gratitude and satisfied NFR. Implications of the current model for integrating previous findings are discussed.     

Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.